It is known that a composition for administering to the rectum, which is represented by a usual suppository being administered to the annal region of the rectum, moves from the site where it is administered to the upper region of the rectum with the passage of time, because the suppository base melted by the body temperature and liquefied. Also, an inside temperature of the rectum of human beings varies depending upon the individual differences in body temperature. Furthermore, when the body is affected by pyrexia or pathopoiesis of the rectum, the inside temperature of the rectum changes within a wider range than that in a normal physiological condition of the body. Melting and spreading of a suppository at the annal region of the rectum immediately after the administration reduce the amount of the effective ingredients existing around the annal region of the rectum. For this reason, there have been reported a number of suppository compositions for curing hemorrhoids which control the spreading of molten suppository existing around the annal region of the rectum so that the effective ingredients of the suppository act effectively to the affected regions.
Further, in the usual suppositories, the shape of composition changes with time due to elevation of temperature during storage, etc., and the deformation sometimes is so serious as to make the suppository unusable.
The present applicant reported in WO99/17737 a suppository composition containing a C10-12 fatty acid glyceride, which can be kept unmolten in spite of the body temperature even when it is held by the fingers before the insertion into the rectum, melts after the insertion into the rectum, but is free from further spreading of the melted suppository to the upper region of the rectum. However, it has been found that this suppository composition gives stimulation such as congestive hemorrhage or expansion of the rectum mucosa when incorporated with lidocaine, lidocaine hydrochloride, dibucaine, dibucaine hydrochloride, procaine, procaine hydrochloride or ethyl aminobenzoate.